Light sources are used to test the performance of charge couple devices (CCDs). Common sources used today include combinations of red, green, and blue LEDs. Individual control of each color LED is required to achieve the desired spectral illuminance during testing. The LEDs are distributed in a printed circuit board such that spectral non-uniformity is minimized. Any optical component, especially lenses, in the light path of the LEDs will also cause the intensity of light to become non-uniform making it difficult to measure intrinsic CCD uniformity accurately.
Consequently, a need exits for a method of testing image sensors such as CCDs that compensates for non-uniformity of optical components.